Finally figured out what was happening - max speed was about 125 even with no wing - it was GEM - there is an evil little check box that overrides the grand prix car and gives you a novice trainer even when you select standard chassis! Took that off and soon I was crashing at 180... its much tougher - I thought the 69's were a bit boring up til now!
Mind you - I can't complete a lap now <sigh>